Spurred by the allegations that the American Enterprise Institute sought to "buy scientists" to challenge the IPCC report, four Democratic Senators wrote to AEI President Chris DeMuth to challenge AEI's actions and demand an apology. In their letter, Senators Bernie Sanders, Patrick Leahy, Dianne Feinstein, and John Kerry, alleged that if the published reports that AEI sought to "bribe" scientists were accurate, "it would be both disappointing and inexcusable." The Senators further proclaimed that they "would not stand silently by while organizations attempt to undermine science through offers of significant amounts of money." The letter concludes:

We hope that you will respond to this letter by telling us that the news reports that you offered to pay scientists up to $10,000 are incorrect. If not, we trust that AEI will publicly apologize for this conduct and demonstrate its sincerity by properly disciplining those responsible.

In the meantime, it is clear that the Senators were not reserving judgement about AEI's alleged conduct. In a press release about the letter, Senator Sanders declared:

It's outrageous that a right-wing think tank with ties to Big Oil and the Bush Administration is trying to twist scientific findings for their political purposes on the pressing issue of climate change. . . . The IPCC report confirms the urgency of the problem and adds to the scientific consensus that global warming is happening now and is human-caused. Is there no limit to the lengths that some corporate-funded groups will go to protect their donors' short-term profits? Is the fate of the entire planet not important enough for them to put the common interest above their narrow self-interest? The truth is that this scandalous behavior on the part of AEI is just the latest example of how big money interests distort and undermine honest debate on the important issues facing our country in so many areas.

AEI President Chris DeMuth did not take this lying down. His strongly worded response (complete with attachments) is posted on AEI's website here. Writes DeMuth:

I am saddened that you would not only believe the reports but would seek to give them credence by repeating them in ways that are even more reckless than the original article published last Friday by the Guardian.

The accusations of the Guardian article, and of your letter, are false. I sent around a memorandum to my AEI colleagues the day the article was published, attaching the letters we had sent to various scientists and policy experts knowledgeable about climate change issues . . . . Relevant portions of these documents were in circulation on the Internet last weekend and in the press earlier this week; they were readily available to anyone on your staffs who had wished to look into the matter or to call me or anyone else at AEI about it. . . .

The accusations of your letter, while couched in the form of questions and insinuations, are as I said harshly worded, and are extremely serious coming from four members of the United States Senate. And they are leveled at a long-established research institution, familiar to all of you, which takes the integrity and independence of its research equally seriously . . . . So it is not a rhetorical question to ask whether you stand by your letter and think it was well-considered.

Finally, I must take exception to your pointed opening reference to "the depths to which some would sink to undermine the scientific consensus that human activity is the major source of global climate change." I believe you have overstated the scientific consensus on the subject, but, even if you have not, I find it worrisome that four powerful political leaders would object to scientific dissent per se. Although you later give a formulaic nod to the right of dissent, you object to being paid a "significant" sum for dissenting research, which rather limits your conception of permissible dissent.

Consensus--and freedom to challenge consensus--are equally vital to the progress of science. History, including recent history, is replete with examples of expert consensus that turned out in the fullness of time to be mistaken. When I look over AEI's publications and conferences on climate change issues, I can indeed find arguments against (as well as for) aspects of IPCC modeling and other matters where some have urged that public debate should cease. I want you to know that AEI will continue to sponsor research and host speakers on climate change issues whose views we regard as reasonable and worthy of attention--never seeking to undermine any consensus for its own sake, but also never paying heed to whether particular views are in or out of official favor. AEI scholars have stood in opposition to established orthodoxy many times; we cherish our intellectual freedom and are proud of the uses we have made of that freedom; we will not be silenced by threats to that freedom.

The Wall Street Journal editorializes on the exchange here.